Friction feed device



March 31, 1970 DVORAK 3,503,603

FRICTION FEED DEVICE Filed Feb. 2'7, 1968 2 Sheets-Sheet 1 IN VENTOR THOMAS DVORAK March 31, 1970 1'. DVORAK 3,503,603

FRICTION FEED DEVICE 2 Sheets-Sheet 2 Filed Feb. 27, 1968 INVENTOR THOMAS DVORAK United States Patent 015cc 3,503,603 Patented Mar. 31, 1970 3,503,603 FRICTION FEED DEVICE Thomas Dvorak, Norristown, Pa., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed Feb. 27, 1968, Ser. No. 708,557 Int. Cl. B65h 3/30 US. Cl. 27123 8 Claims ABSTRACT OF THE DISCLOSURE A document feeder is provided in which a first friction roller contacts the document stack near its trailing edge and a second friction roller having a lower peripheral velocity contacts the document stack near the leading edge thereof. The difiference in peripheral velocities of the two rollers causes the lead document of the stack to bow outwardly from the stack and to thus separate the documents. A third reversely driven friction roller located on the stack side of the document transport path and down the path from the second friction roller acts to shear from the lead document any subsequent documents.

This invention relates in general to a document feeder mechanism and in particular to an economical yet reliable mechanism for feeding documents such as business machine cards from a stack.

Various type mechanisms such as picker knives, rotating belts, friction or vacuum feed roller arrangements have been used in the past for feeding documents from a stack. Most of these schemes have been expensive to fabricate and maintain for one reason or other. In contrast to the prior art schemes the present invention is economical to manufacture and maintain; allows the reliable feeding of documents locked together by friction, punched holes etc.; permits feeding of documents without damage thereto; and permits the feeding of badly mutilated or otherwise damaged documents.

BRIEF SUMMARY In accordance with the present invention means are provided to feed documents one at a time from a stack into a document transport mechanism. As will be described, the documents are preliminarily separated at the stack by moving the trailing edge of the lead document of the stack with a higher velocity than the leading edge of the document. This action causes the lead document to bow outwardly from the stack and thus provides means for separating the documents in the stack. In a preferred embodiment this action is obtained through the use of a pair of friction rollers one of which is located near the trailing edge of the stack and the other of which is located near the leading edge of the stack. The trailing edge friction roller is driven so as to provide a higher peripheral velocity than the leading edge friction roller. A third continuously driven counter rotating friction roller located on the stack side of the document transport path and down the path from the leading edge friction roller acts to shear away from the lead document any subsequent documents which might cling to the lead document. To assist the third roller in its action an idler roller is located adjacent to the third roller and is arranged so that as the card or document leaves the stack it will pass between the idler and third roller and the idler will cause a partial wrap of the document around the third roller thereby providing a large surface of engagement between the document and the third roller. This will assist the third roller in stripping the subsequent document from the lead document and Will permit the third roller to drive the subsequent document back into the stack,

In reference now to the figures:

FIGURE 1 shows a top elevational view of one embodiment of the invention;

FIGURE 2 shows a side elevational view of FIGURE 1; and

FIGURE 3 is an underside view of the structure shown in FIGURE 1 and shows one typical arrangement for utilizing a belt drive for the various rollers in FIGURE 1.

Referring now to the drawings, 10 represents a base plate which may form part of the supporting structure of a card reader, a card punch, a sorter or etc. in which the present invention can be utilized. In a typical example the base plate 10 would be mounted horizontally in the structure. Supported on the base plate 10 is a document hopper 11 which may comprise upstanding sidewalls 12 and 13 and rear wall 14. The bottom of the hopper 11 may be formed by the base plate 10 and may include as an example a pair of guide channels 15 and 16 on which a document feed pressure plate 17 is guided. In practice the guide plate 17 may be spring loaded by means, not shown, so as to urge the documents represented at 18 toward the open end of the hopper 11.

Mounted at the open end of the hopper 11 in engaging relationship with the documents 18 are a pair of friction rollers 19 and 20. The friction rollers 19 and 20 each comprises a metal shaft 19a and 20a on which has been bonded a high coetficient of friction material such as natural rubber. The shafts 19a and 20a are vertically supported on the base plate 10 by suitable bearing means 1% and 20b. The ends of the rollers 19 and 20 terminate on the underside of base plate 10 in a pair of pulley members and 20c. The pulleys 19c and 20c are linked by a common belt member shown in FIGURE 3 as 20d.

The counter rotating stripping roller is shown in FIG- URES l and 2 at 21 and this roller may be preferably made from a plastic material having a coelficient of friction somewhat smaller than the rollers 19 and 20. Roller 21 also includes a shaft member 21a which is journaled in a bearing 21b in the base plate 10. Roller 21 like rollers 19 and 20 terminates on the underside of base plate 10 in a pulley member 210. The idler roller is shown in the drawings at 22 and is mounted on an adjustable carriage 23 which has screw adjustments 24 located in the base thereof to permit the idler roller 22 to be adjusted along a center line which parallels the vertical center line of roller 21 as viewed in FIGURE 1. In practice the clearance between the idler 22 and roller 21 may be adjusted to be about 2 card thicknesses. Positioned down the document feed path from the reverse roller 21 and idler 22 are a pair of rollers 25 and 26 which may represent the initial gripping rollers of a document transport system not shown. Each of these rollers 25 and 26 is vertically supported as indicated in FIGURE 2 on the base plate 10 and roller 26 which may be considered as the driven roller of the pair includes a pulley member 26a.

The gripping drive roller 26 and the continuously rotating stripping roller 21 may both be driven from a common belt member as shown at 27 in FIGURE 3. As shown in this figure the common belt 27 loops around a drive pulley indicated at 28 which may be driven by a motor, not shown, then around the gripping drive roller pulley 26a, then around idler pulley 29, then partially wrapped around the counter rotating roller pulley 210 back to the drive pulley 28.

In operation, the drive pulley 28 is continuously rotated to thus continuously rotate the feed roller 26 and the counter rotating stripping roller 21. To feed cards, a solenoid actuated snub roller as shown in FIGURES 1 and 3 at 32 may be driven by a solenoid 33 into wedging engagement with counter rotating pulley 21c and the pulley 190 of roller 19. This may be done by energizing the solenoid 33 with a control pulse applied to terminal 34 from a control'system, not shown. Upon energization of the solenoid 33, roller 32 will transfer the motion of the belt 27 to the pulley 190 to cause .roller 19 and hence" roller 20 to rotate As better shown in FIGURE 3 the diameter of the pulley 190 is larger than the diameter of pulley 20c so that the roller 20 will rotate with a higher peripheral velocity than roller 19. After the lead document has been moved to a point as indicated in FIGURE 1 where it is engaged by the initial gripping rollers 25 and 26, and before the trailing edge of the document leaves roller 20 the solenoid 33 is deenergized. At this time the gripping rollers 25 and 26 pulls the card from the stack and feeds it into the transport system. To control the deenergization of the solenoid 33 a leading edge detector may be located in the vicinity of the rollers 25 and 26 to detect the presence of the document and deenergize the solenoid 33. As an alternate arrangement, the solenoid 33 can be energized by a control pulse of suitable duration which will bring the lead document to a point of engagement with the gripping rollers 25 and 26 and at that point automatically terminatel To facilitate removal of the document from the stack once it has been gripped by rollers 25 and 26, means may be provided for declutching rollers 19 and 20. This may be accomplished by coupling pulley 190 to shaft 19a by a standard type one way clutch.

As shown in FIGURE 1, the document leaving the stack follows a somewhat serpentine path and the purpose of this path is to cause the document to partially wrap-around the counter rotating roller 21 to thereby assure good stripping action thereby. This serpentine path is achieved as follows: the rollers 19, 20,.21 and 22 all have diameters and locations such that a line drawn tangent acrossthe tops of rollers 19 and 20 as viewed in FIGURE 1 will lie between a similar line drawn tangent to the bottom of roller 21 and the center of roller 21. Likewise a similar tangent line drawn across the top of idler 22 will lie between the center of roller 21. and the aforementioned roller 21 tangent line. By so locating the .rollers the document being fed from the stack will wrap partially around the roller 21 as indicated.

In a typical example of a structure built to handle business machine cards, rollers 19 and 20 each had an outside diameter of .950 inch while pulley 190 had a diameter of .620 inch and pulley 20c had a diameter of .535 inch. The diameter'of roller 21 was .750 inch and of roller 22 was .750 inch. The horizontal center lines of rollers 19 and 20 as viewed in FIGURE 1 were vertically displaced downward .733 inch from the horizontal center line of roller 21. Continuing as viewed in-FIGURE 1 the vertical center line of roller 21 was displaced .772 inch from thevertical center line of roller 19 and .223 inch from the vertical center line of roller 22.

As shown in FIGURE 1, the pressure or feed plate includes a nub or rib-like protrusion 17a' which is posiway between the rollers 19 and 20. This rib 17a acts to concentrate the pressure of the plate"17 on the'docur'nents at a point essentially midway between the rollers 19 and 20 thereby assuring a good gripping action of these roller s with the documents. A bow limit plate 35 is located between the rollers 19 and 20 to prevent the documents from being pushed out of the hopper 11 by the bowing action of rollers 19 and 20.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: a

1. A document feeder mechanism for feeding documents one at a time from a stack of documents comprising, a first friction roller adapted to continuously engage a document stack near the trailing edge thereof, a second friction roller adapted to continuously engage the document stack near its leading edge, and drive means selectively coupled to said first and second rollers for Simultaneously driving said rollers in similar directions, said drive means including a means for causing said first roller to impart a higher velocity to the lead document in the stack than the second roller and thereby to cause the lead 7 document to bow outwardly from the stack.

tioned on the plate 17 so as to lie approximately mid- 2. A structure as described in claim 1 wherein the last named meansincludes a pulley coupled to each of said rollers and a belt linking said pulleys, the pulley coupled to said first roller having a smaller diameter than the pulley coupled to said second roller.

3. A structure as set forth in claim 1 wherein said rollers have similar coefficients of friction and similar diameters.

4. A structure as set forth in claim 1 wherein the drive means includes means for clutching the rollers off and on upon demand.

5. A structure as set forth in claim 1 wherein there is included a counter rotating roller located near the second roller on the stack side of the document and down the transport path therefrom.

6. The structure set forth in claim 5 wherein the counter rotating roller has a lower coeflicient of friction than the first and second rollers.

7. The structure set forth in claim 6 wherein there is further included an idler roller arranged so as to cause the document leaving the stack to partially wrap-around the counter rotating roller.

8. A structure as set forth in claim 1 wherein there is included a pressure plate member engaging the document stack and being operated to urge the documents of the stack toward the first and second rollers, said pressure plate member being formed so as to concentrate the pressure on the documents in the area between the rollers.

References Cited FOREIGN PATENTS 932,551 7/1963 Great Britain.

RICHARD E. AEGERTER, Primary Examiner 

